<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <div class="box2"></div>
  <div class="box"></div>

  <div id="app">
    <h1>{{msg}}</h1>
  </div>
  <script src="https://cdn.jsdelivr.net/npm/vue@2.7.16/dist/vue.js"></script>

  <script>
    const app = new Vue({
      el: '#app',
      data: {
        msg: 'Hello Vue!'
      },
    })
  </script>
</body>

</html>